The present invention relates to board based recreational devices like skateboards and mountain boards.
There are many types of board based recreational devices. These include skateboards with four wheels for operation on pavement; mountain boards with four wheels for operation on rough terrain and inline skateboards for operation on pavement.
The prior art includes a plurality of mountain boards with four wheels that extend above the level of the board. For example, U.S. Pat. No. 5,794,955 describes such a four wheel mountain board.
The prior art includes U.S. Pat. No. 5,160,155 which discloses a skateboard having two wheels in tandem. This patent also discloses a spring based mechanism for dampening and centering the front steering wheel. The front steering wheel is positioned rear of the point of pivot between the wheel and the skateboard.
It is an object of the present invention to provide an articulated two wheel board device for operation on rough and smooth terrain.
It is a more particular object of the invention to provide a board that is made up of two sections, the front board member and the rear board member.
It is another object of the invention to provide a pivot point where the front board member connects to the rear board member.
It is another object of the invention to provide a rear wheel that extends behind the rear board member and above the level of the rear board member and attached to the rear board member. It is another object of the present invention to provide a front wheel that extends in front of the front board member and above the level of the front board member and attached to the front board member.
Preferably the front wheel is connected to the front board member by means of a front fork member which attaches to the front wheel axle.
Preferably the rear wheel is connected to the rear board member at the rear pivot point by means of a rear fork which attaches to the rear wheel axle.
It is another object of the invention to provide the pivot point which includes thrust bearings, thrust bearing races, a pivot bolt and a pivot nut.
In some embodiments there is a flexible rod that runs under the board members along the long axis the length of both board members and is attached at one end to the rear fork member and the other end at the front fork member
In some embodiments the board member is constructed of 13 ply birch which gives it great stiffness and can support the pivot point.
In some embodiments the board member is constructed of different material.